Power Talk
June 2015 | EPECentre, University of Canterbury
West Wind farm, courtesy of Michael Campbell, EPECentre Scholar
Director’s Column
By EPECentre Director, Allan Miller
In previous newsletters we have talked about trends in enrolments in electric
power engineering and some of the factors influencing enrolments, as well as the
EPECentre’s outreach activities and new scholarships for school leavers. The new
EPECentre scholarships have been announced to schools for the second year, with
a series of five informational posters this year to promote them, posted to every
secondary school in New Zealand. The EPECentre team has made an excellent job
of these posters, and we invite you to view them on the EPECentre’s web site
at www.epecentre.ac.nz. The purpose of the posters is not only to advertise the
scholarship, but to inform and promote electric power engineering as an area of
study and a career, consistent with the EPECentre’s outreach activities.
A large part of our outreach activities has involved hosting secondary schools in our
laboratories, to experience electric power engineering first hand. While the College
of Engineering buildings are being refurbished and we are in temporary premises,
we have only been able to host a limited number of local schools in the high voltage
lab. However we have used it as an opportunity to develop the learning resources,
to take electric power engineering at the University of Canterbury to a national
audience, which has always been the aim of our promotion. I am very pleased to
announce the launch of the EPECentre NCEA Electrical Systems Guide, available
from the EPECentre web site at www.epecentre.ac.nz. A lot of people from the
EPECentre and College of Engineering have been involved in the development of
these videos, and their efforts and this result is thoroughly appreciated. Shreejan’s
article in this newsletter takes a closer look at the NCEA Electrical Systems Guide
and the next steps for it.
In addition to developing the guide, the EPECentre has continued its GREEN Grid
research, with six papers to be presented at the 2015 EEA conference. Three of
those papers are summarised in this newsletter, one about the economics of
EPECentre Power Talk 2015
Contents
pg 1 Director’s column
pg 2 Welcome to
pg 2 Public lecture on EVs
pg 2 Outreach
pg 3 Events
Research Papers
pg 4 The Economics of Photovoltaic Solar Power
pg 5 Environmental Aspects of Photovoltaic Power: The New Zealand Context
pg 5 The Benefit of Electric Vehicles for Demand Response
EPECentre Scholars
pg 7 Former Scholar
pg 7 Current Scholar
pg 7 Undergraduate Scholars
pg 8 Key dates 2015
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photovoltaic solar power (PV), another about environmental
aspects of PV, and a third about the use of electric vehicles
for demand response. We preview one of the EPECentre’s
former scholars and a current scholar, introduce the 2015
EPECentre scholars, and as always, finish with the calendar
of EPECentre events for the remainder of 2015.
Welcome To
The EPECentre welcomes three new staff members who
have recently joined. They are: Danica Nel, who has
been helping with administration and will be working on
the EPECentre’s web site until the end of August; Linsey
Mackenzie who joins in July as PA and Administrator; and
Tim Crownshaw who is on a secondment from Transpower
for six months, working on the GREEN Grid project. We
also welcome two new Ph.D. students: Luke Schwartfeger
who started on 1 March 2015 and Michael Campbell who
started on 2 June 2015.
Outreach
By Shreejan Pandey
Electrical Systems Field Guide
In 2014 we published the paper “Zen and the Art of
Engineering Education”, in which we examined NCEA
statistics, surveyed students, and interviewed a number
of secondary school teachers. The paper identified that
approximately 50% of Year 13 students enrolled in Physics
are either not achieving or choosing to not participate
in the electrical systems NCEA examination (NCEA 3.6,
“Demonstrate understanding of electrical systems”). From
the surveys we concluded that students find electricity
difficult to understand, and are likely to choose alternative
options in an effort to gain higher grades (achievement
certificates and course endorsements). Furthermore,
teachers are in need of resources and training programmes
to maintain or build their knowledge of electrical systems
and subsequently teach and inspire students.
Public Lecture on Electric
Vehicles
The University of Canterbury holds a fortnightly public
lecture series called the “What If” lectures. Allan Miller
delivered one of these on 27 May, entitled “What if we all
drove electric vehicles”. The 200 person lecture theatre was
sold out, with many questions after the lecture, followed
by a demonstration of a model of Michael Faraday’s
rotating wire experiment - the world’s first electric motor.
A video of the lecture is available through the University of
Canterbury’s What if Wednesday page:
www.canterbury.ac.nz/wiw/
Discovery of Electromagnetism is explained in the film “Electric
Generators and Electromagnetism”
Insufficient numbers of electric power engineering
graduates has been a topic of discussion for over a
decade in our industry. Our immediate response following
our research was to launch the new UC EPECentre
undergraduate scholarships programme in order to attract
and support high quality school leavers to Electrical
and Electronic Engineering (EEE) degree study. We are
currently offering eight of these scholarships on an annual
basis with financial support from members of the Power
Engineering Excellence Trust. The promotional collateral
for these scholarships offer educational content that aims
to teach prospective EEE students about power systems,
while profiling former EPECentre scholars and example
careers. Our 2015 promotional posters are available on the
EPECentre web site for those interested in viewing them:
www.epecentre.ac.nz
Allan Miller, “What if we all drove electric vehicles” lecture
EPECentre Power Talk 2015
In order to provide learning and teaching resources
to schools, we expanded our EPECentre Outreach
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Programme to develop a set of learning resources
designed to complement NCEA Electrical Systems Levels 1
– 3 curriculums. We recently launched our online based
“NCEA Electrical Systems Guide” (ESG) with educational
films that have been specially developed to capture NCEA
students’ interest and demonstrate the fundamentals of
DC Electricity and Electromagnetism. Over the course of
this year and beyond, we will be continuously improving
the ESG by developing and adding new content such as
games and experimental worksheets. The guide is available
on our web site.
secondary school students in the high voltage laboratory
for demonstrations and careers information. These are
held throughout the year and offered to Canterbury and
West Coast schools that have a strong interest in Electrical
Systems. The forthcoming North Island Field Trip will take
30 undergraduate students enrolled into EPE courses (or
prerequisites) around the country to visit our members’
sites. The four day field trip will take students to generation
plants (wind, geothermal, hydro, coal and gas), substations
and switchyards (including the HVDC site), and distribution
sites. The field trip will also include a formal visit to a Marae
where students will learn about the importance of Maori
values and partnerships in our industry.
In February we invited four recent UC graduates from
generation, transmission, distribution and consulting
sectors to share their student and professional engineering
experiences to a new cohort of Electrical and Electronic
Engineering (EEE) degree students. The forthcoming
Careers Convention provides an exclusive opportunity
for our members to communicate opportunities in the
electricity industry for EPE graduates, and promote
summer and graduate recruitment opportunities directly
to EPE students.
Pierce Hennessy explains how electric vehicles work in the film “Electric
Vehicles and DC Electricity”
GREEN Grid, funded by MBIE, Transpower and the EEA,
is a six year research programme that we are leading
and working together with Universities of Auckland
and Otago to ensure that New Zealanders have access
to reliable, safe, and affordable renewable energy. The
GREEN Grid conference is an opportunity for researchers
to communicate findings of relevance to the electricity
industry, and wider stakeholders. This year GREEN Grid
conference is being held at the University of Canterbury on
25 November and is open for all to attend.
Students from John Paul II, Greymouth in the UC HV laboratory
Events
By Shreejan Pandey
We run a number of events throughout the year to promote
the Electric Power Engineering (EPE) education, increase
the interaction between professional engineers and our
students, and communicate our research findings. Key
dates and details of EPECentre events are published on the
back of this newsletter.
Due to the College of Engineering refurbishment works,
we have only been able to host a limited number of local
EPECentre Power Talk 2015
EPECentre Careers Convention 2013
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The Economics of Photovoltaic
Solar Power
By Allan Miller
A recent review of the uptake of photovoltaic solar power
(PV) in New Zealand shows it continuing to rise, as indicated
below. Analysis of the figures in more detail, by customer
type, shows some interesting trends. Specifically: in the six
months to February 2015, the rate of increase of commercial
PV grew, but the rate of increase of residential PV slowed.
This confirmed our suspicions, and led to more interest
in our investigation of the economics of PV for residential
rooftop systems and commercial systems. Out of interest
we also investigated utility scale PV systems. The work was
carried out from the point of view of the investor in PV
systems (to ask the question: is PV a viable investment?),
and to compare PV with other forms of generation.
The EEA paper “Economics of Photovoltaic Solar Power
PV may now be an attractive investment. However the
attractiveness of PV depends on a household’s financial
position and access to finance; some households may seek
low risk investments, making their cost of capital lower
than say a family with a mortgage, or a family who finds
finance very difficult to obtain.
The results also show that commercial PV is an attractive
investment in some cases, although the returns are very
sensitive to: (1) location in New Zealand; (2) retail variable
price of the electricity supply; and (3) discount rate. The
same factors also cause considerable variability in utility PV
returns, which are shown to be the worst returns, mainly
because the energy is sold at the spot price, the average of
which is substantially lower than the retail variable price.
The following graph compares the levelised cost of energy
Investment Required
Type
Residential, 4% discount rate
Residential, 7% discount rate
$10,500
Commercial, 14c/kWh
Retail rate
$125,000
Utility
$4,000,000
Location
Christchurch
Auckland
Nelson
Christchurch
Otago
Auckland
Nelson
Christchurch
Otago
Best NPV
($,000)
7
3
3
13
-5
-24
-719
-738
-128
-1,848
Worst NPV
($,000)
-1
-3
-18
-10
-25
-40
-1,270
-1,289
-1,740
-2,209
PV returns by customer type
PV cumulative capacity to February 2015
and Uptake in New Zealand” gives more information
about where in New Zealand PV uptake is occurring, and
by residential and commercial systems. It also gives more
detail about the results of our economic investigation,
which are summarised in this article.
Different measures were required to (1) understand the
economics from the point of view of the investor and (2)
compare PV with other forms of generation. For the former
we used net present value (NPV), while for the latter we
used levelised cost of energy (LCOE).
The results, summarised in the table in the net column,
show that residential returns depend to a very large extent
on the household type and their electricity use, especially
during the day. This is not surprising, as using the energy
generated by PV to offset a house’s load effectively earns
the variable retail rate, whereas selling excess PV energy
earns the much lower retailer buy-back rate. We examined
a number of types of household to give a range of returns
– these are shown in the full paper, which demonstrates
the considerable variation in load profiles between houses.
The results show that for the higher user households,
EPECentre Power Talk 2015
between the different types of PV, with ranges representing
differences between location and discount rates. Other
forms of renewable generation are still lower cost, such
as wind at around 4-11c/kWh and geothermal at around
7-14c/kWh (both from the 2014 Lazard report). Even lower
in cost is energy efficiency, which would therefore be the
logical place to start for residential and business customers.
The analysis of PV at the utility scale gives more of an equal
comparison with other forms of generation, since it sells
at the spot price. It should be recognised that much of
Levelised cost of energy of PV. Note that the costs used for utility scale
PV were very low, which is why its LCOE is so low
the individual benefit from residential and commercial PV
schemes arises because of the use of variable charges to
recover fixed costs of the distribution network. However,
the savings made by customers who avoid that component
of the variable charge, do not necessarily reflect an actual
reduction in the costs of transmission, distribution, or
retailing. Future work could consider the economic benefit
of PV to New Zealand as a whole, based on an assessment of
the true marginal cost from distributed PV in transmission,
distribution and retailing.
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Environmental Aspects of
Photovoltaic Power: The New
Zealand Context
By Luke Schwartfeger
The attraction of photovoltaic (PV) solar power in New
Zealand is manifesting as a rapid uptake of PV systems
across residential and commercial rooftops. Over 2014,
this uptake equated to approximately 3,760 panels
installed each month. A major reason to install PV is the
financial savings the owners may receive. However, solar
power can also contribute to New Zealand’s renewable
energy generation and our greenhouse gas emission
reduction targets. Just like the economic benefits of PV, the
environmental impacts are not clear. To understand this
further, we researched the environmental aspects in the
New Zealand context. This article briefly presents some of
the findings. For the full story we encourage you to read
the 2015 EEA Conference paper, “Environmental Aspects of
Photovoltaic Power: The New Zealand Context,” which will
be available on the EPECentre website after the conference.
There are two major factors that determine the
environmental impacts of PV panels: (1) the technology
type and (2) the electricity generation mix of the country
they were manufactured in. The two main technology
types are crystalline silicon (c-Si) and thin film. Crystalline
silicon is the dominant type installed around the world and
accounts for around 90% of the panels produced in 2013.
Although thin film only accounts for a minor proportion
of the installations, it has an advantage of only requiring
23% to 40% of the energy to produce compared to
crystalline silicon panels. This directly ties into the second
major factor, namely the electricity generation mix that
supplies the manufacturing plants. More than 80% of the
electricity generation in the countries that are the major
suppliers of PV panels (China, U.S.A, Japan and Europe)
is thermal based. Combined with the energy intensities
of the different technology types, PV panels have large
embodied greenhouse gas (GHG) and acidifying emissions
which results in increased climate change impacts and
acidification of land and waterways, respectively. The
acidification effect is only experienced in the region where
the thermal generation is located; hence any PV panels
installed in another country do not offset them.
Although PV panels do have an overall positive impact on
greenhouse gas emissions over their lifetime regardless
of the installation location, the magnitude of the benefit
differs greatly when considering the technology type and
the electricity generation mix. The image below shows the
difference in GHG emissions payback period in New Zealand
between c-Si and thin film (CIGS and CdTe) technologies
and being European and Chinese manufactured.
EPECentre Power Talk 2015
GHG Emissions Payback Period
PV panels can aid New Zealand’s goals towards its 90%
renewable energy target by 2025 and our greenhouse
gas emissions targets. For the latter, PV can contribute by
offsetting thermal generation. The issue with this is that
unlike other nations, New Zealand’s electricity grid is highly
renewable and contributes less than 10% of New Zealand’s
total GHG emissions (see figure below). This reduces PV’s
potential benefit in this area. Although the uptake of PV
is rapid, there was only 20.2 MW installed in New Zealand
at the beginning of 2015 which would only contribute a
minor amount of energy to New Zealand. With regard to
New Zealand’s 90% renewable energy target, it is unlikely
that PV will contribute much toward that in the near future.
This is largely due to the low generation potential of PV in
Emissions history and future targets
New Zealand. However, as PV panel efficiencies improve,
there is a chance that it may be installed to cater toward
energy demand increases. At present, PV in New Zealand
has positive, but limited, environmental benefits for the
country and globally. It would be advisable for New Zealand
to focus on other solutions to reach our renewable energy
and emissions targets, such as encouraging the uptake of
electric vehicles.
The Benefit of Electric Vehicles
for Demand Response
By Allan Miller
Plug in electric vehicles (EVs) with inbuilt battery storage
enables the concept of using their batteries to supply the
grid when it is in need of electricity. En masse, thousands
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of electric vehicles might provide a substantial amount
of demand response. Indeed the concept of vehicle-togrid (V2G) has been around for some time, where an
electric vehicle can charge from the grid, or supply the
grid, depending on the needs of either. The idea of V1G
has also been around for some time, which is controlled
unidirectional charging of an EV based either on grid
conditions or user preferences. What has not been clear is
the economic viability of these ideas in practice, which led
us to investigate the economics as part of the GREEN Grid
project. We also decided to look at the economics of other
demand response methods, such as simply charging the EV
during the night, as well as the case of using a fixed battery
to store night rate energy to power a house during the day.
It was important to understand the impact on the battery
life of cycling energy through the battery more frequently –
the V2G case. To do this we built a model to track the charge
cycle of an EV battery. In turn the model provided estimates
of the cost associated with battery life degradation under
different scenarios, which needed to be netted off the
benefits from arbitraging energy from low prices to high
prices. We used the spot price as the signal for when to
charge from the grid or supply the grid (V2G), or regulate
the charging rate (V1G). Since the spot price varies by
location, we also looked at the benefits of V2G and V1G
by major centres. Night rate and day rate tariffs also vary
markedly by location, so we also examined the benefits of
charging on night rate by main centre as well.
For the study we assumed use of a Nissan Leaf which has
a 24kWh Li-ion battery, and which travels at least 4.7km
per kWh. We also modelled the average daily energy use of
the EV, which was necessary to ensure the EV had sufficient
charge at the end of the charging period for the daily
commute. Average daily commutes vary by regional centre,
between 20km and 31km per day. It was also assumed that
the vehicle was unavailable for charging between 8am
and 6pm (because it was in use for commuting) and that
the home had a 14kW charger (practically that is unlikely,
as most households are not capable of supplying this
much power. More likely is 7kW, 32Amps). Charging rate
depended on state of charge, and was determined from
EPECentre measurements of battery charging.
The results, tabulated below for a battery cost of $500/
kWh, show little benefit in V2G, some benefit in V1G, but
significant benefit in night rate charging, depending on
location. Full results are given in the EEA paper “Electric
vehicles and demand response.”
Net benefit of V2G
(2012 spot prices)
Net benefit of V2G
(2013 spot prices)
Net benefit of V1G
(charging below
$50/MWh)
Net benefit to charge
on the night rate tariff
compared to the day
rate
Auckland
12.97
4.61
31.41
90.18
Hamilton
12.16
5.78
30.53
70.23
Wellington
13.89
4.03
29.19
169.8
Nelson
1.78
4.26
21.48
127.93
Christchurch
2.54
4.27
20.28
337.44
Dunedin
2.89
3.79
17.44
254.11
Summary of net annual benefits across different charging schemes
We were initially surprised that V2G did not give more
benefit. However on examining it further, V2G is constrained
to trading energy within relatively short time periods (within
a night) and not between them; otherwise there could be
substantial loss of utility of the EV (it might not be available
to drive in the morning due to low charge). Further, within
this period, the theoretical maximum amount of energy
that can be used from the battery is 24kWh. Even with
a price spike of around $2,000/MWh in a single trading
period, 24kWh of energy traded would gross only $48, and
such price spikes are very uncommon (in 2012 and 2013 at
least). Furthermore, this spike would need to occur when
the EV is plugged in and charging, the charger would need
to know about it in advance, and it would require a fast
charger (capable of pulling the entire 24kWh out of the EV
in the single trading period). The majority of homes will not
have fast chargers installed, as supplying 48kW in a home is
simply not possible.
We therefore think that, at present, night rate charging is
the most economical means of charging, because of the
net gains, and that it can be achieved with the EV’s built
in timer and charger. In the future, as EVs become more
common, V1G may take on more importance, combined
with smart grid charging to ensure not all vehicles charge
at once. V1G may also be useful in providing ancillary
services, such as frequency keeping, which could return
even more benefit to the EV owner. However we think that
the most important consideration to the EV owner is going
to be a fully charged EV at the start of the day for the daily
commute. More details are given in the EEA paper.
The Nissan Leaf charging
EPECentre Power Talk 2015
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Former Scholar:
Kelsey Keenan
Kelsey completed her Bachelor of Engineering with Honours
in 2013. Kelsey commenced her career with Meridian
Energy as a summer student and joined the company’s
three year graduate programme in 2014. She has been
involved in decommissioning projects at the Benmore
Hydro Dam and Local Service reviews for the Waitaki Valley
Stations. Asked what motivated Kelsey to pursue a career in
EPE and what she likes about her chosen profession, Kelsey
said, “The EPEC power field trip was a big help in making
the decision to do power engineering, and now that I am, I
can’t imagine doing anything else. I enjoy the scale of the
work involved, the people, and the unique challenges that
the New Zealand system poses.”
was awarded the GREEN Grid PhD scholarship earlier this
year and hopes to study variability in the long term in the
New Zealand electricity grid and identify cost-effective
management methods to ensure security of supply.
Luke is presenting his paper, entitled, “Environmental
Aspects of Photovoltaic Solar Power”, at the EEA 2015
conference; it will be made available on our website
following the conference.
Kelsey also features in the “Electric Generators and
Electromagnetism” film, an educational resource available
for viewing in the EPECentre NCEA Electrical Systems Guide.
www.epecentre.ac.nz/fieldguide
Luke Schwartfeger, EPECentre PhD scholar
EPECentre Undergraduate
Scholars
By Shreejan Pandey
Kelsey Keenan, former EPECentre scholar
Postgraduate Scholar: Luke
Schwartfeger
Luke Schwartfeger completed his Bachelor of Engineering
with Honours in 2013 and was awarded a 2013 GREEN
Grid research summer scholarship at the EPECentre.
Luke’s research paper, “Review of Distributed Generation
Interconnection Standards”, compared the national
and international standards on the interconnection of
distributed generation, and was well received at the EEA
2014 conference, where he received the “Best Paper Student” award. Luke then gained some entrepreneurship
experience with a company he co-founded, SelfieBot. Luke
EPECentre Power Talk 2015
Following the June 2014 announcement and subsequent
promotion of our new UC EPECentre undergraduate
scholarships scheme, we received a high quantity of
applicants from high achieving students from around the
country. Following careful evaluation of each applicant, we
selected and awarded scholarships to our eight scholars,
based on a combination of their personal statement,
academic merit and character.
In addition to this new scholarship scheme, we are phasing
out the existing undergraduate scholarships scheme this
Left to right: Joshua Barry, Kerry Clapham, Piers Landon-Lane
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year by offering five (previously ten) $5,000 scholarships to
EEE students enrolled in Electric Power Engineering (EPE)
courses.
Key Dates in 2015
Date
Event
Detail
22 June 10 July
Outreach
Workshop 2
Secondary school students
from various schools visit UC to
participate in labratory workshops
and career seminars.
Secondary schools are welcome to
contact us for more information and
to participate in this programme.
7 - 10 July
North Island
Power
Systems Field
Trip
Thirty Electrical and Electronic
Engineering students visit power
generation, transmission and
distribution sites.
28 July
Careers
Convention
EPECentre/PEET members
promote summer and graduate
opportunities to Electrical and
Electronic Engineering students for
recruitment purposes.
23
September
R&D Expo
An event where EPECentre
scholarships are awarded, projects
by Electrical and Electronic
Engineering students, EPECentre
staff and associates are presented
to the industry.
25
November
GREEN Grid
Conference
EPECentre hosts the GREEN Grid
research conference at UC.
Left to Right: Caitlin Wood, Jeremy Penrose, Hugh Hendrickson, Clement
Yeo, Kaitlyn Ingram
UC EPECentre Scholarships
Up to eight scholarships are available for school leavers
interested in pursuing the Electronic Engineering degree at
the University of Canterbury. Each scholarship provides up
to $15,000.
Applications close 15 August.
More information about the scholarship and application
process is available via our website: www.epecentre.ac.nz
Contact Us
The EPECentre is currently located on the ground floor of the ICT building
at the University of Canterbury, access is off University Drive, Ilam
P: 3 364 3057
F: 3 364 3783
E: info@epecentre.ac.nz
www.epecentre.ac.nz
EPECentre Power Talk 2015
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